How do you rewrite 3sinθ+cosθ as a sum?

2 Answers
Nov 23, 2016

We know that sin2θ+cos2θ=1. Isolating cos2θ, we have:

cos2θ=1sin2θ

cosθ=1sin2θ

3sinθ+1sin2θ

Hopefully this helps!

Nov 23, 2016

Given expression

=3sinθ+cosθ

2(32sinθ+12cosθ)

2(cos(π6)sinθ+sin(π6)cosθ)

2(sinθcos(π6)+cosθsin(π6))

2sin(θ+π6)
(applying formula sinAcosB+cosAsinB=sin(A+B)